Industrical robots are equipped with a hand commonly called a gripper for holding and manipulating articles during manufacturing processes. Generally, gripping fingers are provided which are optimized for the handling of a particular type of component or workpiece. Conventional grippers are able to move their fingers to a few predetermined positions suitable for a particular object.
Most grippers only have preset open and closed positions. In the open position they provide a space large enough for the fingers of the gripper to be positioned at each side of the object to the manipulated. In the closed position the gripper holds the object firmly without crushing it. The shape of the particular fingers helps hold and control an object when the gripper is in the closed position.
An example of a conventional robot gripper is disclosed in U.S. Pat. No. 4,336,926 to Inagaki et al. The Inagaki et al patent discloses a pneumatically operated manipulator having two fingers 10, 11 which are driven by a chain drive in equal amounts in opposite directions. The fingers are therefore made to come together at an exact gripping center of the device.
The Inagaki et al device appears to be an improvement in the art of effective robot manipulators. This device, however, as with most other conventional robot grippers does not address problems arising from the increased usage of flexible manufacturing systems.
Flexible manufacturing systems are designed for use with a number of different products, components and work pieces. This flexibility increases the value of automation by spreading the great expense of procuring automation equipment (robots) over a multitude of products. Enabling robots to be utilized for manufacturing a variety of goods results in a sharp reduction in overhead cost as compared to older conventional equipment which was specifically optimized for a single component or product and incapable of working with a variety of components that a company produces.
The need for a robot gripper suitable for use with a variety of components has been particularly felt in the electronics industry. One use of electronic grippers is for retrieving electrical components from a standardized form tray in which they are stored. Different inserts in different parts of the tray are generally used to accommodate a mix of components including the typical axial, radial and can type components. Typically, a multitude of these components are knit onto an integrated circuit board in order to complete a circuit board assembly. Use of different robot grippers to grip each different type of component results in high assembly line start up costs. This is particularly true since the components and circuit board are quite small and require miniature robot grippers and manipulators.
In view of the above, a need exists for a robot gripper suitable for use with a variety of different components.
A further need exists for a compact robot gripper suitable for use with a variety of small electronic components.